The ANSI/ESD S20.20 static control standards does not offer a minimum resistance reading. Strictly in terms of grounding static charges, any floor with a resistance <1 x 109 meets the 2014 version of ANSI/ESD S20.20 and is considered acceptable.
While S20.20 does not specify a lowest acceptable resistance, for best practices the flooring industry has historically set the minimum resistance at no less than 2.5 x 104, or 25,000 ohms. This number was based on a defunct NFPA test method, requiring a resistance test with 500 volts of DC current applied to the surface of the flooring material. Current standard test methods apply much lower voltage and yield higher readings.
A floor measuring 25,000 ohms using the NFPA test method would yield a far lower resistance reading with less applied voltage.
ANSI/ESD standards do not offer a minimum resistance requirement because the built-in resistor in the ESD footwear required in manufacturing and handling spaces protects the wearer from potential electric shocks. In data centers, call centers, FAA flight towers, 9-1-1 dispatch centers, and other spaces where ESD-protective footwear is not required, materials with electrical resistance below 2.5 x 104 are considered a potential safety hazard.
For this reason, telecom and Federal Aviation Administration standards prohibit the use of flooring materials with resistance below 1 x 106 in spaces where energized equipment is used.
With Staticworx ESD flooring, you never have to choose between performance and aesthetics. Our beautiful, high quality ESD carpet tile, vinyl, EC rubber tile and sheet goods, and ESD epoxy floors are as beautiful as they are functional.